They are high in fat, but here is a trick if you don't mind using a syringe. Add water into a syringe, then stick it in the body of the wax worm and immediately put it in front of your cham. Try to give him/her one in advance to make sure that he/she will take the worm so you don't kill one for no reason. This method has been very effective for me! (I have tried it with silk worms, seems easier with wax worms)
David